Being partial to anemones,I would have to say the anemonefishes. They do not harm the reef,they are good community fish(as long as you are only keeping one clown or mated pair),and they will also take residence in LPS corals,hairy shrooms,and occasionally star polyps and xenia. Grammas,tangs,blennies,gobies,damsels(especially chromises),firefishes,and the clowns.